A mathematical model of mass transport through dispersed-phase networks to be used for the sustained release of drugs or other solutes at steady races is presented. The drug is assumed to be encapsulated within the dispersed microdomains and transported to the bulk by diffusion across the interface. A drug is released to the surroundings by diffusion through the bulk. The results show that the desired steady flux of a drug to the surroundings may be obtained given appropriate values of structural properties of the network. These properties may be manipulated easily in the fabrication of dispersed-phase networks reported previously.